The present invention relates generally to commercial refrigerator units of the type which have glass doors for viewing merchandise from the front side thereof, and more particularly, to lighting systems for illuminating products contained within the refrigerator.
Commercial refrigeration units of the type employed in supermarkets and other commercial establishments typically comprise a plurality of swingable insulated glass doors which are adapted to permit viewing of merchandise within the refrigerator by passing customers. It is necessary that the products be displayed in a pleasing and visible manner while the doors are in their closed positions. For this purpose, it is customary to employ a vertically disposed fluorescent light on at least one side of each door in order to illuminate the merchandise contained within the refrigerator. Heretofore, this has presented various problems.
Since the light intensity dramatically reduces at farther distances from the light source, items closely adjacent the light source typically are brightly lit while the items spaced horizontally from the source by substantial distances often are not sufficiently illuminated. Such inconsistency in the lighting effect on the goods can be very distractive. This problem is particularly troublesome in refrigerator units because the colder the fluorescent bulb becomes, the lower is the light output, which further reduces the illumination of products which are located further away from the bulb. Moreover, it is desirable that the light not be directed outwardly of the display case in the direction of the customer to create a glare. Indeed, in long refrigerator units which have a multiplicity of pairs of swinging doors, and hence a multiplicity of vertical lights, the outward shining of the lights creates what is referred to as a zebra effect, which again is distractive to displayed merchandise.
Various approaches have been taken for overcoming the foregoing problems, but none have been entirely satisfactory. Utilizing a translucent cover over the fluorescent lamp serves to soften the light output, but does not correct the uneven distribution of light on the displayed goods. Attempts to focus the light output through lenses have not been successful. Focusing lenses have limitations which heretofore have prevented the light from being diffused uniformly on the goods, or which have prevented the elimination of the zebra effect.